Just like C-900u, our top-end model, new LECUA 1000 that is the integration of a highly precise attenuator that is switched by the electronically-controlled fixed resistance and an amplifier circuit part, is embedded in an unbalanced configuration as the sound volume adjustment mechanism that is the fundamental function of a control amplifier. This system is extremely insensitive to external vibration and change in sound quality depending on the volume positions, and also its durability is significantly high. The number of steps is increased from 72, the preceding model’s to 88 and this makes more delicate sound volume adjustment possible within 0 to -87 dB without deterioration of sound quality. Because LECUA 1000 control is used for balance adjustment between right and left, there is no need to worry about sound quality deterioration. The latest version, ODNF4.0 circuit, that has achieved primary slew rate speed indicating the startup performance by feeding back only distortion components, ultra-wide bandwidth, and low level of distortion is adopted for the combined amplifier circuit. ODNF 4.0 has acquired higher performance by making the first stage of the main amplifier 4 parallels, second stage Darlington connection, and the first stage of the error detection amplifier 3 parallels. The distortion characteristics at high frequencies in particular has been significantly improved by minimizing the amount of feedback and enhancing the S/N performance.
* LECUA is an abbreviation of Luxman Electric Controlled Ultimate Attenuator.
* ODNF is an abbreviation for "Only Distortion Negative Feedback".
In order to embody the philosophy of "Power Amplifier Driver" meaning a component to powerfully drive the power amplifier connected to the next stage, a high-power power supply environment with a large-capacity OI-type power transformer and 2 units of 3,300μF block capacitors is secured. This circuit strongly supports the sound quality of C-700u from the bottom.
The dimmer function-equipped FL display with a high level of visibility can display in 4-fold zoom by operating the remote control while it usually displays the input and sound volume in a 2-stage fashion, and the display is also eye-friendly from the listening position.
C-700u is equipped with an unbalanced external pre-input terminal to which the pre-amplifier output terminal of your AV system can be connected. The phases (No. 3 (HOT), No. 2 (HOT)) of the balanced input can be switched and memorized in every terminal, which is useful for connecting to foreign-made components.
New LECUA 1000 uses the arrangement of substrates in three dimensions, i.e. 3D layout to both minimize the signal route and improve its efficiency. The ultimate solution as a control amplifier is realized by the direct connection between the attenuator circuit and amplification circuit eliminating the idea of independent individual circuit blocks.
A loopless chassis structure is used for the cabinet to eliminate increased ground impedance and the effect of generated magnetic field. Gradation cast-iron insulator legs are attached to prevent resonance thanks to its characteristics of that the metallic structure becomes smaller from the center to the periphery of the leg.
C-700u consists of original custom parts such as resistances, capacitors, even all wires, which have been designed or selected from Luxman's highly advanced know-how and sensibility accumulated in producing audio products for a long time, considering the sound quality as the first priority. Those parts have contributed to the realization of rich tone that Luxman has pursued.
The slim aluminum remote control that provides comfortability in hand allows users to operate a wide variety of functions of C-700u such as input selection, sound volume adjustment, zoom display, dimmer function, loudness function,from the listening position.